triceps (triseps)

and n. [NL., II. n.; pl. tricipites (trī-sip'i-tēz). A tricipital or three-headed muscle, which has a triple origin and proceeds to a single insertion; espe Trichia cially, such a muscle of the fore or hind limb, expre ly named as in the following phrases.Triceps extensor cruris, or triceps femoral is, the extensor of the leg upon the thigh, and in part the flexor of the thigh upon the pelvis, considered as consisting of three parts the rectus femoris, arising from the anterior border of the ilium, and the vast us intern us and vast us extern us, arising from the front and sides of the femur. Also called quadriceps extensor cruris when the cruræus muscle is considered as distinct from the vast us extern us. The single tendon incloses the patella, and is inserted into the tuberosity of the tibia. See third cut under musclel. - Triceps extensor cubiti, or triceps humeral is, the three-headed muscle which extends the forearm upon the arm, and draws the humerus backward. It is composed of a long or scapular head, arising from the axillary border of the scapula, and an inner and outer or two short heads, arising from the back of the humerus, separated by the musculospiral groove and nerve and superior pro fund a artery; the three are inserted together into the olecranon. Also called tri ceps brachii. See third cut under muscle1.